This invention is in the field of testing systems, and is particularly concerned with testing of automatic target recognizers. Such recognizers are becoming common in military scene-monitoring systems such as televison and infrared viewers. The target recognizers may be used for monitoring scenes and thus relieving fatigue of human operators, or for training such operators. For whatever purpose such recognizers are used, a need has arisen for some means of rapidly evaluating their performance. The instant invention fulfills this need.